This is the best way I have found to tune a car to get the fastest time possible. Tthis tuning method plus the right shift pattern and your car should run at its best. this works for almost every car i have used it on.
Below are Links to some of my CSR2 playlists and a few others good things, like my CSR2 guide/tutorial playlist which will show you how to tune a car and other good stuff, Just scroll down to see those and Thanks for watching, I hope my videos help..

-CSR2 Guide/Tutorial playlist to teach you all about the game, how to tune your cars
and lots of other great stuff
https://www.youtube.com/playlist?list=PLz4DeT3mE56F2LgraBPtn2rSsqS0FllRr

-How to drive playlist showing shift patterns for different cars
https://www.youtube.com/playlist?list=PLz4DeT3mE56HMiZB3MSl8hafcsw-udk16

-------My other You Tube Channels -----
-Movie reviews you can watch free
https://www.youtube.com/channel/UCyEcB8TsosvGOjSHho9DQNQ
-War robots gaming channel
https://www.youtube.com/channel/UCQ9ru4sI58rEyb9Kpv6FLVw

-I spend a lot of time making videos to help you learn about this game, I don't make much money because of neurological issues i have, bad nerve and muscle problems, if you would like to help out and donate here is a papal donation link https://paypal.me/danieltcaldwell?locale.x=en_US